Handle for pneumatic tools



April2l, 1959 J. E. FEucHT HANDLE: FOR PNEUMATIC TOOLS Filed Nov. l2, 1957 A lun INVENTOR. /f

./Qco E. /CZ-dcf/r ATTORNEY United rates Patent HANDLE FOR PNEUMATIC TOOLS Jacob E. Feucht, Garfield Heights, Ohio, assigner to Westinghouse Air Brake Company, Wilmerdng, Pa., a corporation of Pennsylvania Application November 12, 1957, Serial No. 695,878

6 Claims. (Cl. 137-560) This invention relates to pneumatic tools and linds particular utility in those types of tools which frequently must be turned on and oif. More particularly, the invention relates to an improved shock absorbing handle for such tools, which handle has a conveniently located throttle actuating mechanism that may be actuated without the necessity of the operator removing his hands from the handle.

In handles of the general type to which this invention pertains, the shock of the tool is absorbed by a resilient mounting of the handle. With such an arrangement the handle moves through a considerable arc, pivoting about its point of connection to the resilient mount. The shock of the tool is absorbed by torsional movement in the flexible mounting.

Because the handle swings through an arc relative to the rest of the tool, difficulty has been experienced in providing a suitable actuating mechanism for the pneumatic valve located in the tool body. More particularly, in certain types of tools such as paving breakers, it is highly desirable for the operator to be able to keep both hands on the handle of the tool at all times and be able to actuate the control valve without removing his hand from the handle. However, because a shock absorbing handle contemplated by this invention moves considerably relative to the tool body and its valve, a practical and positive connection between the valve and an actuating lever on the handle has been found to be lacking.

According to the present invention, a pneumatic tool has been provided which has an actuating lever on its handle that maintains a positive operating connection with the valve in the tool body regardless of the position of the handle relative to the body. The arrangement of the parts is such that the operating lever will maintain the valve in the fully depressed position, that is, an on position, regardless of the position of the handle.

Other objects and advantages of the invention will appear hereinafter as this disclosure progresses, reference being had to the accompanying drawings in which:

Figure l is a front, elevational view of a paving breaker embodying a handle made in accordance with this nvention;

Figure 2 is a side elevational view, on an enlarged scale, of only the upper part of the breaker, taken from line 2-2 of Figure l; and

Figure 3 is a sectional plan view of the breaker shown in Figure l, taken generally on line 3-3 of Figure 2 but with parts broken away and removed for the sake of clarity in the drawings.

Referring in greater detail to the drawings, the paving breaker housing comprises an elongated body 5 having a tool 6 extending from its lower end. A compressed air supply conduit 7 extends from the upper end of the body and is attachable to a source (not shown) of compressed air for furnishing the power to reciprocate the hammer 8 to strike the tool 6 in the well-known manner. Secured 2,882,927 Patented Apr. 21, 195,9

to the top of the body 5 by bolts 9 is the backhead 10 to which is welded the clamp boss 12.

A large bore 13 extends through the clampA 12 in which is mounted the shock absorber shaft 14 having a rubber grommet 15 bonded thereto that has a metal sleeve 16 extending over its length. Cap bolts 17 are threadably engaged in the clamp and when tightened tend to close the slot 18 thus securely holding the shaft assembly in place.

A lever arm 19 is keyed to each end of shaft 14 and handles 20, 21 are held captive in the upper ends of the arms by the stud bolt 22 'and nuts 23 and 24. The handle assembly so formed may be positioned in the clamp 12 to the most desirable position for shock absorption and clamped in that position by tightening lock bolts 17. l'

A throttle lever 26 in the form of a bell crank extends through handle 20 and is pivoted therein by pin 27. The lever comprises a hand grip portion 28 which lies adjacent the handle 20 and extends in the same general direction. The lever also includes a Valve contact portion 29 which has a long flat surface 30 adapted to contact the valve 31. In the position shown in Figure l, the handle and valve are in the released or non-operative position.

When the handle 28 is fully depressed by the hand of the operator on handle 20, the lever portion 29 and more particularly the valve contacting surface 30, assumes a position shown by the broken line in Figure l, which is at right angles to the pivot axis of the handles, namely shaft 14. This is important because it insures that the valve 31 will remain fully depressed, and therefore a full air supply will be available, regardless of the position of the handles as they swing in an arcuate path about their pivot axis 14. In other words, the operator pushes or pulls on the handles to vary the feeding pressure or tool retracting pressure and the point of contact of the valve along the length of surface 30 will vary therewith. The contact area 30 of the lever is considerable to insure valve contact regardless of extreme lever positions shown by the broken lines in Figure 2.

By having the lever contact face 30 perpendicular to the handle pivot axis in the on or fully depressed position of the valve, the throttle lever will keep the valve fully depressed in the on position for any arcuate position of the handles.

Compressed air flows from conduit 7 through aligned ports 32 and 33 in the housing 5 and backhead 10, respectively. It then passes through ports 34, 35 and into chamber 36. When the valve 31 is in the position shown, the breaker is inoperative as the spring 37 holds the yO-ring 38 sealed against shoulder 39. The spring seats against the plug 40 which is held in place by threaded plug 41. Another O-ring seal 42 prevents air from leaking past the valve 31 and its sleeve 43.

When valve 31 is moved to the right as viewed in Fig. 3, the seal formed by the O-ring 38 is cracked and compressed air ows from chamber 36 to port 44 to operate the tool in the known manner. When the lever 28 is released, the spring 37 returns the valve 31 to the off position.

The valve is thus easily actuated without the need for the operator to remove his hand from the handle, and yet a swingable shock absorbing handle has been provided. When the operator grasps the handle and valve actuating lever securely, he is assured of full air pressure regardless of any pushing eiort on his part when feeding the drill into the material or any pulling elort when removing the breaker from a stuck steel. The handle can be adjusted to a variety of positions so as to afford maximum shock absorbing characteristics for any particular 3 job and this adjustment can be .enacted Without disturbing or misaligning the'lever and valve relationship.

Various modes of carrying out the invention are contemplate@ as being within the Scope O f the following claimsparticularlypointing out and distinctly claiming the subject matter which is regarded as the invention.

l. AIn a pneumatic tool, a housing, a control valve mounted insaid housing and shiftable between on and off positions, a shocl` absorbing control handle mounted on said housing' for limited swinging movement relative thereto, 'and' a valveactuatingmlever mounted on said handle and having a vsurface engageable with said valve for shitting the latter between o'njand off positions, said urfaie adapted tohold the latter'in said on position dured'rnoveiheutfofsaid handle. v` atilc fl, "a bQSiIis. a Control valve mtiuntd itl' Said 'hilsins'and Shifb between fully n and' of positions, a shocl'cabsorbiig control handlehaving a pivotal connection to said housing tor limited swinging movement relativethereto, avalve ctuatinglever piyotally mounted on said handle and having'a lsurface engageable with said valve for shifting the llatter to said fully on position, saidr surface being disposed at right angles to the axis of said pivotal connection when said valve is in said fully on position whereby said limited pivotal movement of said handle will not alect the position of said valve.

3. In a pneumatic tool, a housing, a control valve mounted in said housing and shiftable between on and ol positions, la shock absorbing control handle resiliently and pivotally mounted on said housing for limited swinging movement vrelative thereto, and a valve actuating lever pivotally mounted on said handle for pivoting therewith and shiitable between valve on and off positions,` said lever having a valve contacting surface engageable with said valve and adapted to hold the latter in said on posil tion during said limited swinging movement of said handle...

4. A pneumatic tool comprising, a housing, a control valve shiftably mounted in said housing between on and olf positions, a shock absorbing control handle resiliently mounted on said housing for limited movement relative thereto, and a valve actuating lever pivotally mounted on `said handle for shifting said valve between on and oit positions, said lever engageable with said valve and adapted to hold the latter in said on position during said limited movement of said handle.

5. A power operated impact tool comprising, a housing, a control valve axially shiftable in said housing, a shock absorbing handle pivotally mounted on said housing and on an axis generally parallel to said valve axis, and a control lever mounted on said handle about an axis substantially normal to said handle pivot axis, said lever having a valve contacting portion for shifting said valve to a fully on position where said portion is substantially normal to said handle -pivot axis.

6. lA power operated impact tool comprising, an elongated housing, a control valve shiftably mounted in an axial direction in said housing, a shock absorbing handle mounted for limited pivotal movement on said housing and on an axis generally parallel to said valve axis, and a control lever pivotally mounted on said handle about an axis substantially normal to said handle pivot axis, said lever having a valve contacting flat surface for shitting said valve to a fully on position where said surface is substantially normal to said handle pivot axis whereby the valve will remain in the fully on position regardless of said limited pivotal movement of said handle.

References Cited in the tile of this patent UNITED STATES PATENTS 

